Source HUD is your heads up display for information that After Effects doesn't show you. Get the layer width and height, and absolute position of each corner—even when you scale and rotate! This also works in 3D. For text layers, you have more info, like character count, word count, and line count.
In addition, there is an automatic mask that is created around your layer that you can use to reveal the layer or even add a box around your text.